1. Field of the Invention
This invention relates to dipole antennas and more particularly, to the improvement of resistive dipole antennas in order to increase the frequency response range.
2. Description of the Prior Art
U.S. Pat. Nos. 3,641,439 and 3,794,914, issued to Edward E. Aslan on Feb. 9, 1972 and Feb. 26, 1974 respectively, disclose instruments for the detection and measurement of microwave radiation over a range of frequencies. These instruments utilize three orthogonally disposed dipoles to produce a relatively broadband isotropic response. In addition, applicant's copending U.S. patent application Ser. Nos. 6,451,041 and 6,451,040, each filed Dec. 20, 1982, disclose unique radiation hazard meters which also use resistive dipole antennas to monitor radiation and display the potential hazard that radiation fields may constitute.
The dipole antennas of such instruments exhibit limitations to the bandwidth of their response as frequency increases. This is because the reactance of the dipole increases with increasing frequency, until it is larger than the resistance, causing a reduction in the antenna sensitivity.
The aforementioned patent applications are concerned with expanding the frequency range of detection instruments and employ both thermocouple and diode sensors in structural arrangements to achieve a broadband response, however, these units do not overcome the bandwidth limitations which are inherent in all known dipole antenna configurations.